Apparatus for hot pressing powdered metals



May 27, 1952 D. RICHARDSON; SR

APPARATUS FOR HOT-PRESSING POWDERED METALS Original Filed Oct. 1, 1945 2 SHEETS-SHEET 1 INVENTOR 13L 07D D. RICHHRDS N SR.

JMMiW ATTORNEY:

y 1952 L. D. RICHARDSON, SR 2,598,016

APPARATUS FOR HOT-PRESSING POWDERED METALS Original Filed Oct. 1, 1945 2 SHEETS-SHEET 2 46 v v 42 W///4\m|u-v/T=4 I lu'vsuroa LLOYD D. RICHARDSON SR ATTURNI'YI Patented May 27, 1952 UNITED STATES PATENT OFFICE APPARATUS FOR HOT PRESSIN G POWDERED' METALS Lloyd D. Richardson, Sr., Spring Valley, Ohio, assignor to H-P-M Development Corporation, a Mount Gilead, Ohio, a corporation of Delaware October 1, 1945.

1950, SerialNo. 156,420

6 Claims.

This application is a substitute application for abandoned, application Serial Number 619,656,

with a minimum lapse of time so that substantially no heat is lost.

It is another object to provide a heating cham her for the aforementioned arrangement which has an induction coil for heating the material.

It is another object to provide fluid operable apparatus for accomplishing the first of the foregoing objects.

It is still another object of the present invention to provide means for preventing oxidation or other chemical reactions of the heated material with the surrounding atmosphere.

These and other objects and advantages will become more apparent upon reference to the accompanying drawings in which:

Fig. 1 is a sectional view through a press adapted for practicing this invention;

Fig. 2 is a partial View of the press of Fig.

,,1 showing the preheating sleeve moved into alignment with the pressing station;

Fig. ,3' is a similar view showing the gate of the heating sleeve actuated to permit the molding material to fall into the die cavity;

Fig. 4 shows the preheating sleeve retracted and the pressing plungers forming the workpiece; and

Fig. 5 shows the workpiece fully formed and being ejected.

Referring to the drawings, there is shown a press comprising a bed I 0 and a head comprising a cylinder I2. Reciprocably mounted in the cylinder I2 is a ram [4 which includes the upper die member IS.

The die member :6 is adapted to be reciprocated into the die cavity [8 by the ram [4. The die cavity I8 is formed by a die sleeve 20 which may include a heating coil or heating passage 22 which maintains the proper sintering tempera- .ture within the said cavity.

- The sleeve 20 is suitably supported in a platen 24 which may have the cooling passages 26 therein to prevent the platen 24 from becoming overheated from the hot die sleeve.

This application April 1 2 A plunger 28 closes the lower end of the sleeve and is mounted on the ram 30 which is reciprocable in the cylinder 32. An adjustable collar 34 and a stop 36 provide for an adjustment which may selectively be made efiective for controlling the uppermost position of the plunger 28, thus providing means for adjusting the capacity of the cavity I8.

The platen 24 is supported on a pair of rams 38 which are reciprocable in the cylinders 40. This is the well known floating arrangement which permits the platen and die to yield downwardly due to the thrust thereon of the powder being compressed in the die cavity.

Reciprocably mounted on the platen 24, in a suitable guide means such as the track. 42, is a chamber 44 formed of insulating material such as ceramic, glass, or plastic having a high melting point. The sleeve 44 comprises a gate 46 having an aperture therein which, when aligned with the aperture in the sleeve 44, permits the material to fall therefrom.

The sleeve 44 is connected to the plungers of a pair of motors 48 which are carried on a bracket stationary with the platen. The motors 48 are adapted to reciprocate the sleeve 44 into a position directly over the die cavity l8.

Attached to the sleeve 44 is a motor 50 which is adapted to reciprocate the gate 46 into position to drop the material from the sleeve 44.

The material within the sleeve 44 is heatedtby a coil 52 which is arranged around or in the said sleeve and which is connected to any suitable source of alternating current energy. This source ma comprise a vacuum tube oscillator, a spark gap oscillator, or a motor generator set. Suitable control means may be provided for energizing the coil 52 for a predetermined lengthof time in order properly to heat the material to be pressed.

The material may be placed within the sleeve 44 from a hopper suitably located, or it may be introduced in the form of precompacted pellets or briquettes which have previously been prepared in another machine.

In order to prevent chemical reactions of the heated material with the surrounding atmosphere, means are provided for blanketing the material in the heating chamber and in the die with an inert or a reducing gas. This may take the form of the pipes and valves at 54 arranged over the heating chamber so that gas may delivered thereto.

The gas may be delivered to the die cavity l8 -by providing the chamber 56 which is attached to the lower surface of the platen 24 and which surrounds the lower punch 28. A pipe 58 and valve 60 provide means for controlling the flow of gas into the chamber 56. A seal 62 seals the aperture through which the punch 28 passes through the chamber 56. The pressure built up in the chamber 56 is sufiicient to force the gas upwardly around the punch 28 and into the cavity l8.

The platen 24 and plunger 28 are reciprocated relatively in order to eject the completed workpiece, and the movement of the heating chamber into position over the die may be utilized to remove the elect from the press.

It will be apparent that various modifications can be made in this arrangement without in any way departing from the basic invention as illustrated in the drawings. For example, various means could be provided for ejecting the workpiece, for providing the inert or reducing atmosphere, for delivering the heated material to the briquetting chamber, operation of the press Without departing from the basic principle of heating the material adjacent the die cavity and delivering it thereto with substantially no delay of time.

While the apparatus disclosed and described herein constitutes a preferred form of my invention, it will be understood that the apparatus is capable of alteration without departing from the spirit of the invention, and that all modifications that fall within the scope of the appended claims are intended to be included herein.

I claim:

1. In an apparatus for compacting powdered metallic materials into workpieces; a die having a cavity; pressing plungers for material within said cavity; a heating chamber of electrical insulating material adjacent said die; a gate in said heating chamber movable into a first position to support the material to be heated and into a second position to permit the material to be expelled from said chamber; an induction coil adapted for being energized to beat the material in the heating chamber; and means selectively operable for moving said heating chamber into alignment with said die cavity,

for thereafter actuating said gate to deposit the heated material in said cavity, and finally to retract said heating chamber from said die during the pressing cycle.

2. In an apparatus for forming workpieces from powdered material; a die having a cavity; o posed pressing plungers reciprocable in said cavity for compacting material therein; a heating chamber also having a cavity and reciprocably supported adjacent and above said die for receiving charges of material to be heated; a member normally forming a bottom for the cavity in said chamber; an induct-ion coil energizable for heating the material in said heating chamber to sintering temperature; and means for reciprocating said heating chamber into alignment with said die and for moving said member out of its bottom forming position for transferring the heated material from said chamber to said die.

3. In an apparatus for forming workpieces from powdered metals; a die; means yieldably supporting said die; a heating chamber carried by said supporting means and including a cavity, a

member to support the material to be heated in said cavity. and an induction coil. said induction coil being adapted for heating material in the cavity of said heating chamber to sintering temperature; means for moving said heating cham her into alignment with said die and for moving saidmember out of its material-supporting posiand for controlling the compacting tion for transferring the heated material from said cavity to said die; and pressing plungers operable to compact the heated material within said die and to eject the finished workpiece therefrom.

4. In an apparatus for forming workpieces from powdered metals; a die having a vertically disposed cavity; upper and lower pressing plungers reciprocable in said cavity; abutment means for halting said lower plunger at a predetermined point in its travel to define a material-receiving chamber of a predetermined size with said cavity; a heating chamber of ectrically non-conductive material adjacent said die and also having a vertical cavity; a member normally positioned in said cavity to support the material to be heated and movable to release said A material; an induction coil encircling said heat ing chamber energizable for heating the material therein; and means for moving said die and heating chamber relatively to bring their cavities into alignment and for moving said member out of its material-supporting position to transfer the material heated in said heating chamber to said die.

5. In an apparatus for hot pressing powdered metals; a die having a cavity; a first plunger normally positioned in said cavity and forming a bottom therefor; a second plunger reciprocable in said cavity for compacting the material therein; a heating chamber reciprocably mounted adiacent said die cavity for receiving powdered metallic material and for heating it therein to sintering temperature; means for reciprocating said heating chamber into alignment with said cavity and for transferring the material heated therein to the cavity of said die; and separate channel means opening into said chamber and cavity, one for providing a continuous supply of controlled atmosphere to said heating chamber, and the other to said cavity, for preventing undesired chemical changes in the heated material during any stage of the operation thereon.

6. In an apparatus for forming workpieces from powdered materials; a die having an openended cavity; pressing means movable longitudinally within the cavity of said die means for compressing materials deposited in said cavity; a heating chamber arranged above the plane of said cavity and movable between a position above and in longitudinal alignment with said cavity and a position in laterally offset relation to said cavity; means connected with said chamher for moving the same between said positions; means disposed above the plane of said chamber when the latter occupies its laterally offset position for introducing powdered materials therein: and valve means carried in said chamber and operable to open said chamber to permit the gravitational passage of materials therefrom when said chamber occupies its position in longitudinal alignment with said cavity.

LLOYD D. RICHARDSON, SR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

